Bacterial binding and bacteria-induced cytokine production in CD163-expressing THP-1 cells. (A) Human CD163 expression on THP-1 cells expressing empty vector (THP EV; filled histogram) or CD163 (THP CD163; open histogram) as analyzed by flow cytometry using the anti-CD163 mAb EDhu1. (B) Binding of DsRed-transfected E coli to THP EV cells and THP CD163 cells as described in “Cell binding assays.” Means plus or minus SD from 3 independent experiments are shown. (C) TNF-α production by THP EV and THP CD163 cells in response to S mutans and E coli bacteria. Bacteria were added in a concentration of 100 bacteria per cell and incubated for 4 hours. Means plus or minus SD from 2 independent experiments are shown. Statistics: 2-tailed Student t test.